How can you calculate your organisation’s carbon footprint?

What’s a carbon footprint?

A carbon footprint is the amount of greenhouse gases (GHGs) an individual or organisation emits. It can be used to measure your entire contribution to GHG emissions, usually over a 12-month period. Or it can be used to measure the emissions associated with one of that organisation’s products or services.

What are Scope 1, 2 and 3 emissions?

An organisation’s emissions are calculated using a defined set of what are known as emission scopes. These are defined by the GHG Protocol:

Scope 1 covers the direct emissions that result from activities within your organisation’s control. Typically, these include onsite fuel combustion and materials processing company-owned vehicles.

Scope 2 covers indirect emissions from energy your organisation has purchased. This is mostly for electricity, heat, steam or cooling.

Scope 3 covers the emissions from all activities which are up– or downstream of your organisation. This could include emissions from:

• Business travel
• Investments
• Downstream transportation and distribution
• Processing, use or end-of-life treatment of sold products

What is a carbon footprint measured in?

The emissions in your carbon footprint include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluorides (SF6). They're expressed in terms of their carbon dioxide equivalent (CO2e). This shows how much CO2 warming each GHG causes.

Why measure your carbon footprint?

Establishing your organisation’s carbon footprint demonstrates that you’re serious about its commitment to sustainability and Environmental, Social and Governance (ESG) issues. This is an area that is becoming increasingly important to shareholders, customers and employees and could bring benefits to your brand. It could even make your organisation more attractive to potential investors.

Measuring your carbon footprint can also help you comply with regulatory and legal requirements. For example, your business may need to do Streamlined Energy Carbon Reporting (SECR) or the Taskforce on Climate-Related Financial Disclosures (TCFD).

The information you gather can help you understand how to use resources more efficiently and keep costs down.

Follow the GHG Principles

The GHG protocol includes a set of principles that every organisation should follow when calculating its carbon footprint. This covers:

• Relevance: ensure that your organisation’s GHG inventory appropriately reflects your GHG emissions. It should meet the decision-making needs of both internal and external users.
• Completeness: report on all GHG emissions sources and activities within the chosen inventory boundary. Disclose this and justify any exclusions.
• Consistency: use a consistent methodology. This way, your emissions can be compared over time. Explain transparently if anything changes in terms of the data, inventory boundary, methodology, or any other relevant factors.
• Transparency: you should address all relevant issues in a factual and coherent manner, based on a clear audit trail. Disclose any relevant assumptions and make appropriate references to the accounting and calculation methodologies and data sources used.
• Accuracy: ensure that any uncertainties are reduced as far as you practically can. Your calculations must be accurate enough for users to make reliable decisions. They must trust the information you report.

How to measure your carbon footprint

Step 1 – Map your operations and emissions sources

First, consider what activities your organisation is involved in across all three Scopes. Consider whether they happen within, upstream or downstream of your organisation.

You can do this with a simple chart e.g.:

Step 2 – Draw your boundaries

Next, decide what you’re going to include. You may not have the data to report everything, although this should be your organisation’s eventual aim. If you don’t have data for Scope 3, then you should focus on the other two scopes. Then you might want to include the upstream part of Scope 3 – it’s simpler to gather the data for that.

Step 3 – Identify your data sources

Here, you’ll need to provide data for the key emission types. But even if you don’t have all the data, you can still use what you do have.

You should provide the start of use date, end of use date, country where used and the supplier who provided the resources you’re reporting on.

Our Carbon Reporting Guide provides guidance on the data needed for key emission types.

Your report should cover a 12-month period and be repeated annually so that progress can be measured against your baseline year. Ideally this would mirror your organisation’s financial year and should cover your stated emissions boundary and estimate for any gaps.

Step 4 – Calculate your emissions

If you want to produce a number that quantifies your organisation’s carbon footprint, then you can produce a spreadsheet using the activity x carbon factor principle.

If you want a more complex answer, there are a number of commercial calculators online that can help.

Step 5 – Report your carbon footprint

Knowing the volume of CO2 your organisation is responsible for makes it easier to understand how much you need to reduce emissions and can inform your future strategy. It can also help you to keep track of how well your efforts are going year on year.

Step 6 – Next steps

You don’t have to wait until you’ve calculated your organisation’s emissions before you act to reduce them. But knowing what your carbon footprint is will help you measure your success.

Best practice when it comes to reducing emissions is to adopt a science-based target. These are targets which align with the latest climate science and show that you’re taking your proportional share of action to combat climate change.

The Science Based Target Initiative (SBTi) operates schemes for large and small organisations. You can sign up for them here.

Don’t forget to communicate your achievements in measuring and reducing your carbon footprint to your stakeholders. Your suppliers will also be interested by your progress. You can encourage then to take steps of their own (which could in turn help you with your Scope 3 reporting.)

Need more help? Download our free Carbon Reporting Guide

Our Carbon Reporting Guide covers the full carbon reporting journey in detailed, easy to understand steps. Download it for free to help your business take action, comply SECR guidelines and start your sustainability journey.